Process of extracting hops.



G. G. SMITH.

PROCESS OF EXTRAGTING HOPS. APPLICATION FILED JUN-319, 1008.

992,275. Patented May 16, 1911.

GEORGE GREGORY SMITH, OF ST. ALBANS, VERMONT.

PROCESS OF EXTRACTING HOPS.

Specification of Letters Patent.

Application filed June 19, 1908.

Serial No. 439,336.

To all whom it may-concern:

Be it known that I, GEORGE GREGORY SMITH, a citizen of the UnitedStates, residing at St. Albans, county of Franklin, State of Vermont,have invented certain new and useful Improvements in Processes ofExtracting Hops, of which the following is a full, clear, and exactdescription.

My invention relates to an improved process of extracting from hops thesubstances used in the manufacture of beer, and particularlycontemplates a process by which that content alone of the hops necessaryto the successful manufacture of beer may be readily segregated andprepared for use in the most effective, and at the same time, economicalmanner.

A further object of the invention is to provide a process whereby theseveral desired constituents of the hops may be fractionated to vary thecharacter of the extract in order to adapt it to the making of beers ofdifferent qualities.

In its broadest aspect, the invention consists in the aqueous extractionand segregation of those properties of the hops employed in themanufacture of beer, by digesting the hops in a sealed boiler at a giventemperature and for an ascertained time, and the subsequent cooling andevaporation of the water of digestion under a given maximum temperature.

For clearer comprehension of the process constituting my invention, Ihave illustrated, in a conventional way, part of the apparatus employedtherein which is shown in the accompanying drawing, in which the figureis a vertical section of the apparatus.

The form of apparatus here selected for illustration comprises acylindrical vessel 1 of copper or enameled iron. It is to be understoodthat no iron should come in contact with the hops.

2 is a dome-shaped plate preferably of copper, located at the bottom ofthe vessel to form a heating chamber at the base, and having openings 2around its perimeter for a purpose hereinafter described. A pipe 3extends vertically therefrom to the upper portion of the vessel 1 andleads through and projects above a perforated copper plate 4, whichforms a cover for the hops.

5 is a baffle plate of substantially mushroom form for distributing thewater of distillation from the pipe 3 over the perfo- Patented May 16,1911. r

rated plate 4, through which the water per- .J colates through the bodyof the hops, which is contained between the plates 2 and 4.

A steam-tight cover 6 is provided for the vessel 1, having projections 7which extend down to and in contact with the plate 4, to

hold the latter firmly down upon the hops during the boiling operation.Thermometers 8 extend through the sides of the Vessel 1 into thehop-containing portion thereof between the plates 2 and 4. A safetyvalve 9 is also mounted upon the cover 6, by which the pressure withinthe vessel 1 may be regulated and controlled.

In carrying out my improved process, the entire hops, that is to say,without previous segregation of the lupulin, are placed within thevessel 1 upon the plate 2, and are submitted to a soaking process inpure distilled water (water containing salts of lime or organicsubstances should be avoided, as

the first tend to harden or combine with the resins and oils in thehops, and the others are offensive). The proportion of water to the hopsshould be approximately seven to ten liters of water to each kilo ofhops, ac-' cording to the age and condition of the latter, and thesoaking process should be continued for a period sufficiently long tothoroughly saturate the hops, at a temperature safely below that offermentation and preferably approximating 16 (3., for a period inpractice often found to be from 8 to 100 hours. By osmotic act-ionduring this soaking process the lupulin cells of the hops are filled totheir utmost capacity, in consequence of which, when the temperature ofthe hops and liquor is raised during the sub sequent digestion, thesecells are all burst and give up the whole of their contents. If thecells do not burst and thus give up the whole of their contents, a largequantity of the resins will not be converted during the digestion into Ivaluable products. That these resins are extracted and are convertedinto valuable products for use in the extract other than the mereexpelling of air from the hops, which is the usual purpose of macerationheretofore employed.

After the soaking process is completed, heat is applied to the bottom ofthe digester 1, whereby the water collected under the plate 2 is forcedby pressure of steam through the pipe 3, and in striking against thebaffle plate 5, is distributed over the perforated plate 4, and afterpercolating through the body of the hops returns to the heatingcompartment below the plate 2. Thus, in effect, a continuous leachingprocess is secured.

The temperature during the process of boiling should never exceed 101 0.and should be maintained as nearly uniform as possible, in order to keepa continuous stream of water percolating through the hops.

In order to extract the entire content of the hops, excepting some ofthe coarser resins, which are never used in the manufacture of beer, theprocess should be continued for suiiicient time, from six to eighteenhours, to soften the resinous portion of the hops, according to the ageand condition of the hops. Experiment with a given sample of the hops tobe digested will indicate the best time during which the digestingprocess should be continued, taking into consideration the kind of beerto be desired for instance, if a light mild beer is desired, the processshould be relatively short as compared with the time necessary to make astrong bitter beer. In fact, an extract may be prepared by my processwhich will be adapted for any quality of beer desired, in so far as itowes its quality to the hops.

The safety valve 9 should be set at a pres sure of from one to threekilos during the entire process of boiling, so as not to act after theexpanded air within the digester is thrown off. This is an extremelyimportant requirement, inasmuch as otherwise the flavor and fragrance ofthe hops will be thrown off with the steam. The mass should then becooled by any suitable apparatus, such as a system of cold water pipesin the digester, as rapidly as possible to approximately 50 0., to avoidthe formation of acetic acid, or any other product of fermentation. Theliquid should then be immediately extracted from the mass of hops bymeans, for example, of a centrifugal machine, such as is used in sugarmaking, or by pressure. If the liquid is allowed to stand, even for ashort time, at above the temperature of fermentation, fermentation willbegin with the accompaniment of acetic acid and other products offermentation, which would vitiate, if not ruin, the entire result. Theliquid should then be immediately evaporated by placing the same in asuitable vacuum pan, such, for example, as is used in sugar making, anda vacuum maintained at not less than 67 cm. The temperature at whichevaporation may be secured should be below that at which volatilizationof the essential oils and ethers or lighter hydrocarbons would takeplace. In any event, the temperature should not rise above 60 0. Inpractice, a temperature should be maintained at say 541 0., and thevacuum at from 73 to 74: cm.

Torecapitulate, the entire process consists in the aqueous extraction ofthe required properties of the hops by soaking the hops to saturation,digesting the mass in a sealed boiler at a temperature not exceeding 1010. for from six to eighteen hours determined by the age and condition ofthe hops, immediate extraction from the hops and then the evaporation ofthe water of digestion at a temperature of about 54 0., but neverexceeding 60 0., whereby only such content of the hops is extracted asis essential to the manufacture of beer of a given quality, and allcontent, foreign or deleterious thereto, is eliminated. The reason formaintaining the temperature specified is that the ethers and essentialoils contained in the hops which constitute the fragrances and flavorsof the proper extract, are most volatile. At a temperature above 60 0.all the more valuable essential oils and fragrances volatilize and arelost. In practice the vacuum caused by the condensation of the steam orvapor in the process of evaporation is not suflicient for evaporation atthe necessary temperatures for making hop extract. It is, therefore,necessary to employ an auxiliary vacuum agent, for example, a mercurialpump.

In order to produce hop extracts adapted for the manufacture of beer ofdifferent qualities, the periods of time and the temperatures abovementioned may be varied within the limits specified, as experience willsuggest.

What I claim is:

1. The process of extracting from hops the substance used in themanufacture of beer, which consists in soaking the entire hops to thepoint of saturation in pure water, then digesting the mass in a sealedvessel at a temperature sufficiently high to burst the cells, but notexceeding 101 0., rapidly cooling the mass below the point offermentation, immediately withdrawing the liquor from the hops, andimmediately evaporating said liquor in a vacuum sufficiently high toevaporate the water at a temperature below that at which the essentialoils and other volatile constituents will volatilize.

2. The process of extracting from hops the substance used in themanufacture of beer, which consists in soaking the entire hops to thepoint of saturation in pure water, then digesting the mass at atemperature sufficiently high to burst the cells, but

not exceeding 101 0., for a period of from a vacuum at a temperature notexceeding 6 to 18 hours, according to the age and con- 60 C. dition ofthe hops to soften the more soluble resins therein, immediately coolingthe mass GEORGE GREGORY SMITH 5 to a temperature below the point offermen- Witnesses:

tation and immediately extracting the liquor RALPH C. POWELL, ofdigestion, and evaporating said liquor in CHAS. A. PEARD.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

